Therapy-related, mixed-lineage leukaemia translocation-positive, monoblastic myeloid sarcoma of the uterus

Exome sequencing analysis of gastric primary myeloid sarcoma with monocytic differentiation with altered immunophenotype after chemotherapy: case report

BACKGROUND

Myeloid Sarcoma with monocytic differentiation is rare and quite likely is missed by surgical pathologists. However it is frequently misdiagnosed because of its non-specific imaging and histological pattern.

CASE PRESENTATION

We report the case of a 64-year-old woman with gastric primary myeloid sarcoma with monocytic differentiatio. Upper endoscopy revealed a neoplastic growth at the junction of the lesser curvature and gastric antrum. Except for a slightly increased peripheral monocyte count, no abnormalities were found on hematological and bone-marrow examination. Gastroscopic biopsy showed poorly differentiated atypical large cells with visible nucleoli and nuclear fission. Immunohistochemistry showed positive CD34, CD4, CD43, and CD56 expression, and weakly positive lysozyme expression. Immune markers for poorly differentiated adenocarcinoma, malignant melanoma, and lymphohematopoietic-system tumors were negative. The final diagnosis was myeloid sarcoma with monocytic differentiation. Chemotherapy did not shrink the tumor, so, radical surgery was performed. Although the tumor morphology did not change postoperatively, the immunophenotype did. CD68 and lysozyme expression (tumor tissue markers) changed from negative and weakly positive to strongly positive, AE1/3 expression (epithelial marker) changed from negative to positive, and CD34, CD4, CD43, and CD56 expression (common in naive hematopoietic cell-derived tumors) was greatly attenuated. Exome sequencing revealed missense mutations in FLT3 and PTPRB, which are associated with myeloid sarcoma, and in TP53, CD44, CD19, LTK, NOTCH2, and CNTN2, which are associated with lymphohematopoietic tumors and poorly differentiated cancers.

CONCLUSION

We diagnosed myeloid sarcoma with monocytic differentiation after excluding poorly differentiated adenocarcinoma, common lymphohematopoietic-system tumors, epithelioid sarcoma, and malignant melanoma. We identified that the immunophenotypic of patient had alterations after chemotherapy, and FLT3 gene mutations. We hope that the above results will improve our understanding of this rare tumor.

Therapy-related myeloid neoplasm with bone marrow involvement, myelosarcoma, and a t(8;16)(p11.2;p13.3)-a case report

Therapy-related leukemia is a well-documented complication of conventional therapy for cancer. Therapy-related acute myeloid leukemia (t-AML) is grouped along with therapy-related myelodysplastic syndrome (t-MDS) and therapy-related myelodysplastic syndrome/myeloproliferative neoplasms (t-MDS/MPNs) as therapy-related myeloid neoplasms (t-MNs) by the 2008 World Health Organization classification system. Therapy-related myeloid neoplasms differ clinically from their de novo counterparts in terms of response to therapy, aggressiveness of disease, and associated poor prognosis. The occurrence of extramedullary myeloid sarcomas with bone marrow involvement has been shown to be a poor prognostic indicator for patients with t-MN. The karyotype of leukemic blasts has also been reported to have a significant impact in t-MN and may predict survival and outcomes in patients. The t(8;16)(p11.2;p13.3) is a rare, balanced translocation that is frequently associated with the M4/M5 subtype of de novo acute myeloid leukemia. It has also been reported in patients with t-MN, typically in those with poor outcomes. Here we report a case of t-MN with myeloid sarcoma and bone marrow involvement in an adult patient with a karyotype of 47,XY,t(8;16)(p11.2;p13.3),+21 after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy for follicular lymphoma.